Corrosion in heat exchangers has long been a problem. It is generally recognized that one of the causes of this deterioration is the electrolytic action between the dissimilar metals of the various components. This process, referred to as electrolysis, produces a flow of current between the two unlike metal areas when in the presence of an electrolyte, such as ionized natural waters, which in turn causes corrosion on the more active metal (anode) and forms a protective film on the less active metal (cathode).
To increase life, a sacrificial material may be used with heat exchangers prone to produce a current flow. Zinc, being very unstable as evidenced by its position in the galvanic series, has been used as a sacrificial material to reduce the deterioration of copper alloy tubes and other metal structures in the highly dense structure of shell and tube type heat exchangers which use ionized water such as seawater or lake water as the cooling medium. One such system is disclosed in U.S. Pat. No. 4,776,392 to Loyd, having an issue date of Oct. 11, 1988. In that system, zinc rods are positioned in the end caps of the heat exchanger and are grounded to the engine using an electrical conducting member. The reaction of the cooling medium and the rod suppresses electrolytic damage to the core.